Nested cables and reel assembly

ABSTRACT

The cord reel assembly ( 10 ) comprises a housing ( 12 ); a spool ( 14 ) mounted for rotation in the housing ( 12 ); an electrical component ( 15 ) carried by the spool ( 14 ); a first cable ( 16 ) having a first end connected to the electrical component ( 15 ), the first cable ( 16 ) being windable onto and off the spool ( 14 ), the first cable ( 16 ) having at least one longitudinal cavity ( 32 ); and a second cable ( 22 ) having a first end connected to the electrical component ( 15 ), the second cable ( 22 ) being windable onto and off the spool ( 14 ), the second cable ( 22 ) being releasably nested in the cavity ( 32 ) of the first cable ( 16 ) when the two cables are co-wound together on the spool ( 14 ).

FIELD OF THE INVENTION

[0001] This disclosure relates to nested cables and to retractable cordreels and more specifically to nested cable and retractable cord reelassemblies for use with laptop computers and other electronic devices.

BACKGROUND OF THE INVENTION

[0002] Internal rechargeable batteries power portable electronic devicessuch as laptop computers. Laptop computers are highly desirable due totheir portability, which is directly related to their size and weight.Even though breakthroughs in computer technology have enabledmanufacturers to miniaturize nearly all the computer components,advances in battery technology have been slow, resulting in littlechange in the size and weight of the batteries.

[0003] The batteries in a typical laptop will power the computer foronly a few hours, which is inadequate for a normal businessperson.Manufacturers prefer smaller batteries because it allows them to marketa smaller, more desirable product, but power capacity (battery life) issacrificed. As a result, laptop users carry their battery charger orelectrical adapter with them to meetings or wherever else they travel,and connect the laptop to high voltage power whenever possible. Becauseof their dependence on computers, businesspersons cannot afford fortheir batteries to ever run out.

[0004] Business people commonly bring their laptops everywhere they goduring the workday (meetings, etc.), as well as home at night and ontrips. This means they also bring the electrical adapter for the laptopeverywhere they go. Laptop manufacturers have been very innovative inimproving the portability of the laptops by adding such features asbuilt-in or foldout mice. But little effort has been allotted toimproving the portability of the electrical adapter that is taken alongeverywhere the laptop travels.

[0005] Typical electrical adapters are a rectangular box about2.5″×4″×1.25″ high. It includes two cables usually about 6 feet long.one for high voltage power (extending from a wall socket to the adapter)and the other for low voltage power (which extends from the adapter tothe laptop). When a person moves from an office to a conference room, hewill simply fold up the laptop, but then must unplug the adapter andmanually (sometimes randomly) coil the cord around his hand or aroundthe adapter. Sometimes the cords are not coiled at all and simplydragged behind on the floor! If a coiled cord is placed on a table or ina brief case, it will begin to uncoil as soon as it is let go. The lackof portability of a electrical adapter is very much out of sync with theexcellent portability of the devices they power.

[0006] Other electric devices also have problems with storage of powercords, particularly where two cords are attached to the same device. Asewing machine, for example, often has two cords extending from the footpedal. House current is delivered to the pedal from one cord, regulatedby a control device and the action of the pedal, then delivered to themachine by a second cord. Storage of the cords and foot pedal can becumbersome. Even when a cord reel is used for one cord, the second cordmust be stuffed in a separate compartment, stored in a separate reel orclumsily wrapped around the foot pedal for storage.

SUMMARY OF THE INVENTION

[0007] These and other problems are solved by the nested cables andretractable cord reel assembly of the invention. A retractable cord reelassembly is described including a housing, a spool rotatably mounted inthe housing, a first cable and a second cable, each at least partlycarried by the spool, and means for releasably coupling the first cableto the second cable when the first and second cables are co-woundtogether onto and off of the spool. Preferably, the releasable couplingof the cables includes nesting the first and second cables together. Oneelement for nesting of the cables includes providing one of the cableswith a longitudinal cavity so that the other cable is nested into thecavity when the cables are wound together. As exemplified in thespecific embodiments below, many modifications may be made forparticular applications.

[0008] One particular embodiment comprises a nested cable and cord reelassembly designed for the electrical adapter for laptop computers andthe cables attached to it. The assembly comprises a housing; a spoolmounted for rotation in the housing; an electrical component, such as anelectrical adapter, carried by the spool: a high voltage power cablehaving a first end connected to the electrical adapter, the high voltagepower cable being windable onto and off of the spool, the high voltagecable having at least one longitudinal cavity; and a low voltage powercable having a first end connected to the electrical adapter, the lowvoltage cable being windable onto and off of the spool, the low voltagecable being releasably nested in the cavity of the high voltage cablewhen the two cables are co-wound together on said spool. The free end ofthe high voltage cable has a plug for connection to a standardelectrical outlet. The free end of the low voltage cable has a plug orother connector adapted for connection to an electronic device, such asa laptop computer. The housing may include pocket(s) or chamber(s) forinternally storing the plugs or connectors.

[0009] The invention is also useful for other electrical devices, suchas a sewing machine. A nested cable and cord reel assembly is suitableto store both the cord delivering power from the house current and thecord delivering the regulated power to the sewing machine with the cordsnested together. The cord reel is optionally designed to fit inside thefoot pedal, which provides a convenient storage location. When it isdesirable to store the sewing machine for later use, both cables arewound together into the cord reel assembly that also houses the powerregulator in the pedal, providing compact and convenient storage of bothcables inside the foot pedal.

[0010] In its retracted state, the high voltage and low voltage plugsare inside the cord reel housing or against the side of the housing, andare easily accessible to the user. The user pulls either the high or lowvoltage cable to extract the desired length of cable. Since both cablesare nested together when wound on the spool, approximately equal lengthsof each cable are dispensed from the cord reel regardless of which cableis pulled. All or part of the cable stowed in the cord reel may beextracted.

[0011] After use, the cord is retracted into the cord reel for neatstorage and portability. Many of known methods can be used to retractthe cable. A spring may be incorporated to bias the spool in the cordretracting direction, and a ratchet can be used to hold the cables inthe extended position until retraction is desired. A motor or hand crankcan also be used to retract the cables.

[0012] In the consumer market where cost is a major consideration, thecord can be manually retracted by turning the electrical housing whileholding the cord reel housing. Since the spool is attached to theelectrical housing, turning the electrical housing causes the spool torotate and the cables to retract.

DETAILED DESCRIPTION OF THE DRAWINGS

[0013]FIG. 1 is a top cross-sectional view of the present nested cablesand cord reel assembly with a portion of the housing and spool cut awayto show the reel assembly and guides;

[0014]FIG. 2 is a cross section of the first embodiment taken along line2-2 of FIG. 1;

[0015]FIG. 3 is a cross section of the first embodiment of the reelassembly that is the same as FIG. 2, but illustrating an alternate cableconfiguration;

[0016]FIG. 4 is a cross sectional view of the cables of the invention,in an unnested state;

[0017]FIG. 5 is a cross sectional view of the cables of FIG. 4, shownnested together;

[0018]FIG. 6 is a cross sectional view of an alternate embodiment of thecables of the invention, shown nested together;

[0019]FIG. 7 is a cross sectional view of a third alternate embodimentof the cables, shown nested together;

[0020]FIG. 8 is a cross sectional view of a fourth alternate embodimentof the cables of the invention, shown nested together;

[0021]FIG. 9 is a cross sectional view of a fifth alternate embodimentof the cables of the invention, shown nested together;

[0022]FIG. 10 is a cross sectional view of a sixth alternate embodimentof the cables of the invention, shown nested together;

[0023]FIG. 11 is a cross sectional view of a seventh alternateembodiment of the cables of the invention, shown nested together;

[0024]FIG. 12 is a cross sectional view of a eighth alternate embodimentof the cables, shown nested together;

[0025]FIG. 13 is a cross sectional view of a ninth alternate embodimentof the cables of the invention, shown nested together;

[0026]FIG. 14 is a cross sectional view of a tenth alternate embodimentof the cables of the invention, shown nested together;

[0027]FIG. 15 is a top plan view of a second alternative embodiment ofthe cord reel assembly of the invention, with a portion of the housingcut away to show the reel assembly and guides;

[0028]FIG. 16 is a front elevational view of the third embodiment of thecord reel of the invention;

[0029]FIG. 17 is a side elevational view of the third embodiment of thereel assembly of the invention; and

[0030]FIG. 18 is a top plan view of the third embodiment of the reelassembly of the invention.

DETAILED DESCRIPTION

[0031] A retractable cord reel assembly, generally designated 10, isdescribed including a housing 12, a spool 14 rotatably mounted in thehousing, a first cable 16 and a second cable 22, each at least partlycarried by the spool, and means for releasably coupling the first cableto the second cable when the first and second cables are co-woundtogether onto the spool. Preferably, the releasable coupling of thecables 16, 22 includes nesting the first and second cables together. Oneelement for nesting of the cables includes providing one of the cableswith a longitudinal cavity 32 so that the other cable is nested into thecavity when the cables are wound together.

[0032] The following discussion is directed to preferred embodimentswhere the nested cables and cord reel assembly 10 is designed for usewith the electrical adapters for laptop computers. The cables arediscussed in terms of high and low voltage cables, as would beapplicable to laptop computers. However, it is to be understood that thecables need not carry high/low voltage and may carry the same voltage.The invention is intended to apply to any plurality of cables or cordsthat may advantageously be wound around a spool for storage. The cablesneed not be of different types and may be, for example, two ends of asingle, continuous extension cord. The electrical component is optionaland depends upon the intended use for the cables. The term “electricaladapter” is used to describe any electrical component, such as an poweradapter, a switch, electrical converter, battery charger or the like.

[0033] Turning now to FIGS. 1 and 2, which shows one embodiment of alaptop computer cord, the assembly 10, comprises a housing 12, a spool14 rotatably mounted in the housing; an electronic converter or adapter15, a high voltage power cable 16, and a low voltage power cable 22. Thehigh voltage cable 16 has two conductors 18 and an insulating jacket 20as seen in FIGS. 4 and 5. The low voltage cable 22 may comprise aco-axial cable having an inner conductor 24, insulating layer 26, outerconductor 28 and outer jacket 30. The low voltage cable 22 may be ofother multi-conductor configurations as well, and is not limited toco-axial. One of the cables is provided with a means for coupling thetwo cables together when they are wound onto the spool 14. The preferredform of coupling is nesting one cable with the other. Other forms ofcoupling means may be used, such as a tongue and groove or lateraldisplacement of the cavity 32 to couple cables together side-by-side.Preferred nesting means is at least one longitudinal channel or cavity32 on one of the cables adapted to receive the other cable.

[0034] FIGS. 4-14 illustrate several alternative embodiments for nestingcables 16, 22 of the invention. FIG. 4 shows the two cables separatedone from the other, and FIG. 5 shows the two cables nested together. Thehigh voltage cable 16 is similar to a typical 2-conductor lamp cord butthe conductors 18 are separated creating a cavity or gap 32 betweenthem. The low voltage cable 22 is a multi-conductor cable covered with ajacket 30 giving it a generally round cross section that fits in the gap32 between the conductors 18 of the high voltage cable 16. Other crosssectional shapes can be used as long as the cables fit neatly together.

[0035] Desirably, the cables 16, 22 have coincident or nearly coincidentneutral axes when coupled so that both cables have the same radius ofcurvature while the nested cables are being wound. The neutral axis is atheoretical line that does not change in length as an object bends. Asthe cables are bent in an arc to be wound around the spool 14, theportion of the jackets 20, 30 on the inside of the arc will becompressed, while the portion of the jacket 20, 30 to the outside of thearc will be stretched. Because the metal conductors 18 are much stifferthan the polymer jacket 20 that surround them, the neutral axis will benear the center of the conductor 18. When the neutral axis of the highvoltage cable 16 is not aligned with the neutral axis of the low voltagecable 22, each cable 16, 22 has a different radius of curvature, and onecable is retracted slightly faster than the other, causing the cables toslide against each other as they are wound. As best shown in FIG. 6, insome applications it is advantageous to move the conductors 18 in thehigh voltage cable 16 so that the neutral axes of the two cables 16, 22will be coincident or aligned when the cables are nested. Although shownin a particular nesting configuration, this option is suitable for usewith any nested cables shown in FIGS. 5-10.

[0036] Both cables 16, 22 are wound on the spool 14, with the lowvoltage cable 22 stowed in between the two high voltage power conductors18. This nesting of the low voltage cable 22 into the high voltage cable16 allows both low and high voltage cables to be wound together,minimizing the space required to stow the cable. Other cord reels thatlay one flat cable on top of the other (e.g., Peterson U.S. Pat. No.4,646,987) work well only with very thin cables. Thick cablesappropriate for power transmission would result in a cord reel of verylarge diameter if stacked in this manner.

[0037] Nesting the low voltage cable 22 along side or in between thehigh voltage conductors 18 results in a smaller diameter cord reel orspool 14. The preferred configuration has the low voltage cable 22nested in between the two high voltage conductors 18, though variationsthat have the low voltage cable 22 along side the pair of high voltageconductors 18 can also be acceptable in some applications. See FIGS.8-10.

[0038] When wound on the reel 14, the longitudinal cavity 32 in the highvoltage cable 16 optionally faces either inwardly, toward the center ofthe reel 14 (shown in FIG. 3), or outwardly, toward the side walls ofthe housing 12 (shown in FIG. 2). Preferably, the cavity 32 facesinwardly, so that when the cables 16, 22 are dispensed, the high voltagecable 16 is on the outside. To extend the cables 16, 22 from theassembly 10, most users pull on the outside cable. In thisconfiguration, the high voltage cable 16 is most likely to be pulled andis better able to withstand the stress because it is generally athicker, heavier cable than the low voltage cable 22.

[0039] In some applications, longitudinal cavity 32 may be formedbetween adjacent windings in cable 16, as shown in FIGS. 11 and 12. Thehigh voltage cable 16 optionally has a first 31 and second 33 groovesthat meet to form the longitudinal cavity 32. When the cables 16, 22 arewound together, the low voltage cable 22 then nests between two windingsof high voltage cable 16. The low voltage cable 22 will fit partiallyinside the first groove 31 of the segment of high voltage cable 16 andpartially inside the second groove 33 in an adjacent winding of cable16. As winding continues and the next winding of both cables arecoupled, the low voltage cable 22 is sandwiched in the grooves 31, 33between subsequent adjacent windings of high voltage cable 16. Althoughthe first and second grooves 31, 33 are shown symmetrically, it iscontemplated that one of the cavities could be deeper than the other.

[0040]FIGS. 13 and 14 show yet another pair of nested cables that isparticularly suitable when both cables 16, 22 are the same size. Each ofthe cables 16, 22 has a longitudinal cavity 32 into which at least aportion of the other cable nests.

[0041] For some applications it may be desirable to removably lock thetwo cables together in a nested configuration. A locking means 35 ispreferably formed by including at least one locking lip 34 on the outeredges of the cavity 32 to grip the low voltage cable 22 once it isplaced within the cavity. See, FIGS. 6, 8 and 9. However, such lockingmeans 34 is not strictly required. See, for example FIGS. 7 and 10,which do not include locking devices.

[0042] A friction device (not shown) is optionally used with any of theembodiments to prevent the cables 16, 22 from unwinding at inopportunetimes. When all of the cables are retracted, if there is very littlefriction in the rotation of the spool 14, the spool may partiallyunwind, for example, as a result of the elasticity of the polymerinsulation being bent as it wraps around the spool during the windingprocess. Use of a friction device would minimize any unwinding tendencyafter the winding was complete, or between turns of a manually woundunit. Devices of this type are well known in the art, for example,suitable friction may be applied by a Belleville or wave spring washeron the spool axis screw.

[0043] An electrical component 15 may be mounted to one side of thespool 14 as shown. The electrical component 15 will take the form of apower converter for computer power cord applications. For sewing machinefoot pedal applications, the component will take the form of a powerregulatory switch. Other applications will require other electricalcomponents as will be apparent to those skilled in the art. For someapplications, e.g., simple extension cords, no intermediate electricalcomponent is required. In such applications, the two cables 16, 22 arespliced or otherwise connected in or adjacent to the reel hub 37, or thetwo cables are formed from two ends of a single cord that passes throughthe hub without modification.

[0044] Referring now to FIG. 15, the spool 14 has a hub 37. Both cables16, 22 are connected to the electrical component 15, if present, at ornear the hub 37 of the spool 14. Preferably, the cables 16, 22 arerouted through a radial opening 38 on the cord winding surface of hub37, then routed through axial openings 39 in the spool 14 for connectionto the electrical component module 15. Optionally, axial openings (notshown) are provided in the spool 14 in the cable winding area adjacenthub 37 to connect the cabels 16, 22 into the electrical component module15, bypassing the interior of hub 37.

[0045] The module 15 is shown as being square, however, alternateconfigurations may be used as desired to achieve the volume required tohouse the electronics and the desired aesthetics. For example theelectrical component could be configured to fit partially or entirelywithin the hub 37 of the spool 14. Preferably, the overall size of theunit is minimized to enhance portability.

[0046] In the preferred configuration, the cord reel housing 12 willhave cord guides and/or rollers 41, shown in FIG. 1, to guide the cables16, 22 into their nested position so they neatly lie flat together asthey are wound on the spool. As the individual cables 16, 22 are fedbetween a plurality of cord guides 41, 42, or a single cord guide andanother stationary element, such as the housing 12, the two cables arepushed together into the nested position due to the limited spacingbetween the guides. One or more separating guides or rollers 42 areoptionally added to separate the cords 16, 22 as they are retracted intothe cord reel 14. If cords 16, 22 become tangled during use, theseparating guide roller 42 prevents the tangled cords from getting stuckin the nesting guides 41. The separating guide 42 can also serve toseparate the nested cables 16, 22 from each other as they are extendedfrom the spool and to act as a stop to block inward movement of a lineplug 48 after it is retracted into the housing 12. This keeps it in theproper place where it is conveniently reached by the user, allowing himto easily pull the plugs 48, 50 and cables 16, 22 from the housing 12for the next use.

[0047] The first embodiment of the reel assembly 10 of the invention hasthe plugs 48, 50 stored on the outside of the housing 12, is shown inFIGS. 1-3. An alternate preferred embodiment is shown in FIG. 15. Thereel assembly 10 comprises a housing 12, a spool 14 mounted for rotationin the housing, and an optional electronics module 15, which comprisesthe electrical component. In the illustrated embodiments, the housing 12covers the circumferential edges 35 of the spool 14 and one side face 36of the spool. The other side of the spool 14 is open to accommodatemounting of the electrical component module 15 onto the spool. Mountingof the electronics module 15 on the rotating spool 14 is preferred tominimize breakage or twisting of the portions of cables 16, 22 near thespool hub 37. The details of mounting a spool 14 for rotation within ahousing 12, and retraction means, such as springs, are known in the art.See for example, Burke U.S. Pat. No. 5,094,396, the disclosures of whichare hereby incorporated by reference.

[0048]FIG. 15 illustrates a housing embodiment having a pocket orchamber 46 for storing the high voltage or line plug 48 and low voltageplug 50 when not in use. Often, the line plug 48 is molded onto the highvoltage cable 16 as an integral part of it. The plug 48 neatly fits intothe housing 12. In this embodiment, the storage chamber 46 for the lineplug 48 is located to one side of the path followed by the cables 16, 22as they are retracted into the assembly 10. Following retraction, theline plug 48 is manually fit into the chamber for storage.

[0049] FIGS. 16-18 show a third embodiment of the reel assembly of theinvention in which the storage chamber 46 is located along the pathfollowed by the cables 16, 22 as they are retracted into the assembly10. As retraction of the cables 16, 22 is completed, the plugs 48, 50are drawn into the assembly 10 and into the storage chamber 46 withoutseparate handling by the user.

[0050] An optional opening 52 in the side of the housing 12 allowsaccess to the plugs 48, 50 when the cables 16, 22 are fully retractedinto the housing. A lever, button, slide or other mechanism (not shown)may also be employed to push or pull the plugs 48, 50 out of the housing12. Where it is not desirable to store the plugs 48, 50 inside thehousing 12, guides 41, 42 are additionally used to prevent the plugs 48,50 from being retracted too far into the housing 12.

[0051] The apparatus of the invention is adaptable for many differentapplications and/or special requirements. For example, some powerconverters require an EMI shield bead, also known as a ferrite bead. Itis often installed on the low voltage cord 22 near the connector. Whenthis occurs, the separating rollers or guides 42 are suitably relocatedor removed to allow room for the bead. The bead can optionally berelocated closer to the low voltage plug 50, incorporated as part of theplug or possibly moved into the power converter housing 15 or spool hub37. Various modifications of the shape or size of the housing 12, orrepositioning of elements to accommodate such requirements areconsidered to be within the scope of this invention.

[0052] The housing 12 of the invention functions to provide forrotational mounting of the spool. The housing may fully involve thespool or it may be partially or fully open. The addition of doors,covers, latches or other optional mechanisms can be added if desired.Preferably, items such as these are omitted in order to minimizecomplexity, cost and the number of parts that are susceptible tobreakage. However, addition of such features is also considered to bewithin the scope of the present invention.

[0053] Accordingly, the co-wound, nested cables and reel assembly 10 ofthe invention is a compact device that conveniently stores the low andhigh voltage power cables inside the housing. It can also house optionalelectrical components. It provides a facile solution to longstandingproblems in the art.

[0054] While particular embodiments of the nested cables and cord reelassembly has been shown and described, it will be appreciated by thoseskilled in the art that changes and modifications may be made theretowithout departing from the invention in its broader aspects and as setforth in the following claims. More specifically, although nested cables16, 22 have been shown and described as the preferred embodiment, onemay design other means for releasably coupling the two cables togetherwhen wound onto the spool 14. Although cables 16, 22 with two conductors18 have been shown, the invention is applicable to cables with one ormore conductors. The roles of the high voltage cable and the low voltagecable may be reversed, or the cables may have the same voltage. Thenested cables of the invention may have utility in applications otherthan retractable cord reels. Whereas the invention has particularutility as a power cord reel for laptop computers, the invention isequally applicable to other electric or electronic devices. Although anelectrical component 15 has been shown and described in a preferredembodiment, other electronic means may be used in other applications,such as a signal amplifier for electronic signal cables. These and otherroutine modifications of the cord reel assembly of the invention willoccur to those skilled in the art. All such modifications andadaptations are intended to be covered by appended claims.

What is claimed is:
 1. A retractable cord reel assembly, comprising: a)a housing; b) a spool rotatably mounted in said housing; c) a firstcable at least partly carried by said spool; d) a second cable at leastpartly carried by said spool: and e) means for releasably coupling saidfirst cable to said second cable when said first and second cables areco-wound together onto said spool.
 2. A retractable cord reel assembly,as in claim
 1. wherein said means for releasably coupling said firstcable to said second cable, comprises nesting said first and secondcables together.
 3. A retractable cord reel assembly as in claim 1.wherein said means for releasably coupling said first cable to saidsecond cable comprises providing one of said cables with at least onelongitudinal cavity, and wherein the other said cable is nested intosaid cavity on retraction of said cables on said spool.
 4. A retractablecord reel assembly as in claim 3 wherein said at least one longitudinalcavity comprises a gap between two conductors within said first cable. 5A retractable cord reel assembly as in claim 3 wherein a portion of saidother cable is nested in said cavity and a second portion of said othercable is outside of said cavity.
 6. A retractable cord reel assembly asin claim 3, further comprising means for releasably locking said othercable in said cavity.
 7. A retractable cord reel assembly of claim 6,wherein said means for locking said cables comprises at least one lipadjacent said longitudinal cavity.
 8. A retractable cord reel assemblyas in claim 1, further comprising means for rotating said spool forretracting said cables onto said spool.
 9. A retractable cord reelassembly as in claim 1, wherein said first cable comprises a highvoltage cable and said second cable comprises a low voltage cable.
 10. Aretractable cord reel assembly as in claim 1, further comprising anelectrical component mounted for rotation with said spool, and whereinsaid electrical component is electrically connected between said firstcable and said second cable.
 11. A retractable cord reel assembly as inclaim 1, further comprising at least one guide member mounted on saidhousing for guiding said first cable and said second cable together onretraction of said cables onto said spool.
 12. A retractable cord reelassembly as in claim 1, further comprising at least one separatingmember mounted on said housing for separating said first cable and saidsecond cable from each other on extension of said cables from saidspool.
 13. A retractable cord reel assembly of claim 1, wherein saidfirst and second cables comprise first and second ends of a continuouscable.
 14. A retractable cord reel assembly as in claim 1, wherein saidfirst and said second cables have free ends, each free end having anelectrical connector, and wherein said housing includes at least onechamber for said connectors.
 15. A retractable cord reel assembly as inclaim 3, wherein said longitudinal cavity in the first cable facesradially toward the center of the reel.
 16. A retractable cord reelassembly as in claim 3, wherein one of said cables have a top surfaceand a bottom surface, a first groove on said top surface and a secondgroove on said bottom surface, said first and second grooves beingradially aligned when wound on said spool to form said longitudinalcavity between adjacent windings of said one cable; said other cablebeing held in said cavity between adjacent windings of said one cable.17. A retractable cord assembly as in claim 1 wherein said first andsecond cables each have a neutral axis, which axes are substantiallyaligned when said cables are coupled.
 18. A retractable cord reelassembly comprising: a) a housing; b) a spool mounted for rotation insaid housing; c) an electrical component carried by said spool; d) afirst cable having a first end connected to said electrical component,said first cable being windable onto and off of said spool, said firstcable having a longitudinal cavity; and e) a second cable having a firstend connected to said electrical component, said second cable beingwindable onto and off of said spool, said second cable being releasablynested in said cavity of said first cable when said cables are co-woundon said spool.
 19. A retractable cord reel assembly of claim 18 wherein:said first cable comprises a high voltage cable; said second cablecomprises a low voltage cable that nests with a longitudinal cavity ofsaid first cable as said cables are wound on and off said spool; andsaid electrical component comprises a power adapter.
 20. A retractablecord reel assembly, comprising: a) a spool; b) a first cable having aplurality of conductors and at least one longitudinal cavity formed insaid cable, said first cable at least partly carried by said spool; c) asecond cable at least partly carried by said spool; and d) a housing,said spool being rotatably mounted in said housing and having at leastone guide member mounted on said housing for guiding said second cableto nest into said cavity in said first cable on retraction of saidcables onto said spool.
 21. A retractable cord reel assembly of claim20, further comprising at least one lip on said first cable adjacentsaid cavity for releasably locking said second cable in saidlongitudinal cavity.
 22. A nested pair of cables, comprising a firstcable having at least one longitudinal cavity; a second cable releasablynested in said cavity; and wherein said first and second cables may benested together or separated in whole or in part.
 23. A nested pair ofcables as in claim 22 wherein said at least one longitudinal cavity isformed by a gap between two conductors within said first cable.
 24. Anested pair of cables as in claim 22 further comprising a locking meansfor holding said second cable in a nested relationship with said firstcable.
 25. A nested pair of cables as in claim 24, wherein said lockingmeans comprises at least one lip on said first cable adjacent saidcavity for releasably locking said second cable in said longitudinalcavity.
 26. A nested pair of cables for winding onto and off of a spool,comprising: a first cable having a top surface and a bottom surface; afirst longitudinal groove on said top surface and a second longitudinalgroove on said bottom surface; said first and second longitudinalgrooves being aligned when wound on the spool to form a cavity betweenadjacent windings of said first cable; and a second cable nested in saidcavity formed between adjacent windings of said first cable.